Thermostatically-controlled damper



L693,0 (50 l. E. SMKTH THERMOS'I'ATIGALLY CONTROLLED DAMPER Nov. 2?, 1928.

Filed Nov. ll, 1926 5 Sheets-Sheet 1 I N V EN TQR.

.5. Sim iii m ATTORNEY.

Nov. 27, 1928. 1,693,060

I. E. SMITH THERMOSTATICALLY CONTROLLED DAMPER Filed Nov. 11, 1926 5 Sheets-Sheet 2 Fig. 2'

IN VEN TOR.

[/"(1 1'): Sin i ih BY um I ATTORNEY N5 2?, 192%. 1 69mm i. E. SMITH I THERMOSTATI CALLY CONTROLLED DAMPER Filed NOV 11, 1926 5 Sheets-Sheet 3 l iNVEm p a I Ira Sm a $12;

' BY M 3? h .Q 5 mw ATTORNEY Patented Nov. 27, teas.

UNHTED stares IRA E, SEEIETH, F STQCKTON, CALIFORNIA.

THERMOSTATICAJLLY-GQNTRULLED Application filed November 11, 1926. Serial No 147,692.

This invention relates to improvements in frame, a vertical member of suitable characdampers to be inserted in air or gas passages of diflerent kinds, the principal object being to provide an apparatus for the purpose, the opening and closing of which, to control the volume of air passing therethrough, is automatically controlled by the heat in or thrown off from the chamber to which the air passes,

and which may be any distance from the H) damper itself.

A. further object is to provide additional thermostat control means, positioned within or adjacent the damper, for controlling the open and closed position of the same accord ing to the heat of the air actually passing through the damper, said means functioning independent of the main control means.

While the damper may be used for different purposes, it have particularly in mind to employ the same in connection with an oil burner operating in a furnace, to accurately control and automatically regulate the supply of air to be fed to the burner as determined by the size of the fire in said burner.

In this manner the oil in the burner will at all times be mixed with'just the right quantity of air for the most efficient operation These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a side elevation of my improved damper apparatus detached. 1

Fig. 2 is a front end View of the same.

Fig. 3 is a fragmentary section of a dampor member taken substantially on the line 33 of Fig. 1;

Fig. 4 is a longitudinal section on the line 4-4 of Fig. 3 showing the damper-shutter operating mechanism.

Fig. 5 is a fragmentary top plan view of the shutter operating rod showing a hand control means appliedthereto.

Fig. 6 is a cross section of the damper drum and shutter.

Fig. 7 is a diagrammatic assembly of a pair of damper units shown in connection with an oil burner and furnace and with a thermostat control switch.

Referring now more particularly to the characters of reference on the drawings, the

05 numeral 1 denotes the main supporting ter, which may be altered as to form to suit difterent requirements. Projecting horizontally trom the frame intermediate its ends is a rigid hollow member 2, secured to and pro ecting laterally from which is ahorizontal drum 3, having opposed openings 4 cut through the periphery thereof in a horizontal plane. Turnably mounted in the drum is another drum 5 forming a shutter, and also havmg opposed openings 6 substantially the same area as the openings d. The sides of the openings 6 however converge from their opposite ends toward the center as shown at 7,. so that the openings are narrowest at the middle and widen out evenly and gradually from that point toward their ends. The purpose of this arrangement will be explained hereinafter. Disposed inside the-shutter at one end is a vertical spiral 8 of thermostatic metal. Une end of the spiral is connected to the central shaft 9 of the shutter, while the other end is connected to another shaft 10, which is separate from the shaft 9 but is longitudinally alined therewith. This spiral is so arranged that when heated and expanding, and assuming that the shaft L0 is held station.- ary, the shaft 9 will be rotated in a direction tending to cause the shutter to open, or in other words to cause the openings 6 to move toward a registering position with the openings 4:.

The shaft 10 projects into and through the member 2 transversely thereof, and outwardly of said member is attached to one end of an adjustable spiral spring 11, which through the medium of the thermostat element 8 and shaft 9 tends to move the shutter to a closing position relative to the drum. Inside the member 2 the shaft 10 carries a pinion 12 which is engaged by rack teeth 13 formed on a horizontal rod 14:. This rod is journaled 1n and projects through the frame 1 and is of course at right angles to the axis of the drum and shutter.

Disposed above and below the rod 14 in vertical alinement with each other and with the rod and supported from the frame 1 are magnets 15 and 16. The armatures 1 7 and 18 respectively of these magnets are pivoted onto projections 19 of the frame 1 which are disposed between the magnets and'the rod 14:, the ivotal connection of armature 17 being so dispesed that said armature will normally drop by gravity away from its magnet core 20. l

cent ends the armatures are provided with vertical extensions 21 which engage adjustable screws 22 mounted in fingers 23 and 241 which are pivoted at one end in common with the respective armatures. The opposite free ends of these fingers are forked to straddle each other and the rod 14 as well, but move 1ndependent of each other. The edges of the fingers opposite to the frame 1 bear agamst a horizontaland transversely slidable plate 25 having a cam surface 26 on its face ad acent the fingers. This plate has a. longitudmal slot 27 through which the rod 14 and a spaced and fixed pin 28 pass, so as to maintain this plate in a horizontal plane while enabling the same to slide to the extent necessary to cause the cam surface to move against the finger edges. The plate has an outwardly project ing car 29 at one end to enable the same to be readily slid along by hand. Outwardly of the plate the rod 1 1 has adjustable nuts or other stops 30 thereon. It will therefore be seen that when the magnets are energized and the armatures engaged with the magnet cores, the free ends of the fingers 23 and 241 will be moved in a direction away from the frame 1 and will bear against the plate 25, which, being backed by the nuts 30, will cause the rod 1% to be moved longitudinally. This will cause a rotation of the shutter 5 from its normal closed position to an open position to take place, through the instrumentality of the pinion and rack mechanism and the thermostat spiral as previously described. The adjustable screws 22 of the fingers 23 and 245 are set so that with the movement of the armatures an equal distance the corresponding fingers will be moved unequal distances. In this case the finger 23 of the upper magnet is shown as being arranged to move further than the finger 24-. of the lower magnet. This of course causes a greater movement of the rod 14: to be had, and consequently the shutter will be opened wider when the magnet 15 is energized, than when the magnet 16 is energized, even though both magnets be functioning simultaneously. Movement of the hand plate 25 will also cause a movement of the rod 14 to be had independent of that'imparted thereto by the fingers 23 and 24. This is because, as will be evident, as the plate is thus moved the distance between the adjacent edges of the fingers and the nuts 30 will be lncreased owing to the wedge-like action of the cam surface 26 of said plate. Since the ngers cannot move in the opposite direction elther when the magnets are energized or when they are deenergized, it will be seen that an outward movement of the rod 14 will be had by manipulation of the plate 25 indeeeaoco pendently of any such movement which may be imparted thereto by the movement of the fingers.

ln addition to screws 22, the member 24 has another adjustable screw 22 therein, adapted to engage a post 22 projecting from frame 1. This engagement takes place when the magnet 16 is deenergized and before the rod 1st has retracted far enough to cause the shutter to completely close. This causes the shutter to remain partially open, evenv when both magnets are deenergized, so that sufficient air, to operate a very low fire at the burner, can still pass through the shutter.

To illustrate the arrangement and operation of my damper structure in connection with an oil burner and furnace arrangement, reference may be made to Fig. 7 of the drawings. In this figure the burner 31 in the furnace 32 is represented as being of that type shown in my Patent No. 1,582,552, dated April 27th, 1926. The operating motor 33 of the burner is mounted on a base 34: from the outer end of which a vertical plate 35 projects upwardly. The motor is enclosed in an air tight chamber by the base, the plate 35 and a cover 36 which is attached to the plate and base and extends to the furnace to surround the firebox opening thereof. This arrangement is the same as that shown in my patent on an oil burner installation No. 1,609,095, dated November 30th, 1926.

lln applying my air supply control damper unit to this arrangement the plate 35 takes the place of the frame 1, the drum 3 being mounted internally of said plate so that one of the drum openings 4 alines with the opening 37 in said plate and is abutted there-- against. The magnets are disposed outwardly of the plate so that the same relative positioning of the parts of the unit is maintained as with the use of the frame 1. Positioned to be influenced by the heat generated by the oil burner is a thermostat switch S of suitable type, preferably such as shown in my Patent No. 1,600,568, dated September 21st, 1926. This switch has two sloping tubes 38 and 39 containing mercury, each tube having a pair of spaced contacts 40 therein normally engaged by the mercury. The tube 39 is set at a greater slope than the tube 38 so that the contacts in the latter will be disengaged from'the mercury before it is in the tube 39. The contacts 40 in the tube 38 are interposed in a circuit C in which the upper magnet 15 is also interposed. while the contacts 40 of the tube 39 are interposed in a circuit C, in which the lower magnet 16 is also interposed. In operation when the main line switch 41 1s open, the magnets are deenergized and the damper shutter will be closed. When the burner is started up the switch 41 is closed and both magnets will be immediately ener gized, since as above stated the contacts 450 in the two thermostat switch tubes are normally an extent as before.

engaged by the mercury, whether the circuits are otherwise closed or not. The shutter will be then relatively wide open, allowing a great volume of air to pass through the damper to the firebox and burner. The extent of opening of the shutter in this case may be regulated by adjusting the screws 22 or by adjusting the nuts 30 on the rod 14. As the burner generates heat the thermostat switch is influenced by such heat, causing the tubes to be moved to lessen the slope thereof. The tube 38 being normally at a lesser slope than the tube 39 the respective contacts 40 therein will be broken before the contacts 40 of the tube 89 are broken. This causes the corresponding magnet 15 to be deenergized without the magnet 16 being affected. The finger 28 (which moves the rod 14 the greatest distance) will therefore be withdrawn from said rod and the latter will move inwardly owing to the action of the spring 11, until engaged and stopped by the finger24. The damper will therefore still remain open but not to as great The difference in the relative area of the two open positions may be adjusted by adjusting the screws 22 which control the movement of the fingers relative to the constant movement of the armatures; A smaller volume of air will therefore pass to the burner, but this is as it should be, since the volume of the fire in the burner has likewise been automatically reduced, as the heat lit) generated thereby has increased. This feature forms no part of the present invention,

' the arrangement used being preferably that shown in said Patent No. 1,600,558 mentioned above. The damper shutter therefore remains partly open as long as the fire is maintained at a corresponding volume. llf the heat should increase so that the tube 39 is moved to break the contacts the magnet 16 will also be deenergized, causing the shutter to be closed unless it is intentionally held open by the hand plate 25. Tn this case, however, the operation of the burner also ceases, as set forth in the above mentioned patent.

Tf when the shutter is open the air entering through the damper should itself become ated, it will influence the thermostat spiral The latter then expands, causing the shutter to be rotated to a more open position independent of the energizing of the magnets. This also is as it should be since the actual volume of a body of heated air passing through a given area is less than that of a similar body of cold air, and a larger opening through the damper must therefore be provided to enable the volume of air passing to the burner to be maintained constant.

The sloping sides 7 of the shutter openings are necessary in enabling this volume to be very accurately maintained.

This is because the air will flow horizontally through the openings, and'not radially of the axis of the shutter, whereas the openings themselves follow a definite arc. The expansionof the thermostat spiral with a difference of say five degrees in heat in the air passing through the damper will cause the shutter to turn through a constant arc regardless of the initial setting of the shutter relative to the exterior, casing. This additional arcu atu o enin will not however rovide an 0 7811111 of the same height in a vertical plane, if such additional opening is formed when the shutter is nearly closed, as if it were formed when the. shutter is wide open. At the center of arcuate extent of the shutter openings, they are therefore made narrower than at the ends, so as to compensate for the difference in the height of the arcuate openings as above described. This Willallow in one case a. wide body of but relatively shallow volume of air to pass therethrough, and in the other case, a relatively narrow but deep volume of air to pass. The slope on the sides 7 is of course figured out so that the volumes of air in the two extremes of setting of the openings, and those at all intermediate settings, will all be equal.

If found necessary an additional damper unit may be mounted in the stack 42 of the furnace. In this case the damper drum 3 is set in the stack with a close fit and so that the openings therethrough are in line with the stack passage. The control magnets of this unit of course are outside the stack and are connected to the thermostat switch S by suitable wiring 43 to work in conjunction with the magnets of the main damper unit.

The shutter and the openings therein are made so as to be perfectly symmetrical relative to the axis, so that the shutter will be perfectly counterbalanced on its shaft 9, and of course will work very freely and with a minimum of power, either of the magnets, the thermostat spiral. or the return spring.

It is to be noted that with a double damper unit installation, as shown. only the damper ahead of the burner or furnace would be provided with the thermostatic spiral or compensator 8.

From the foregoing description it will be readily seen that T have produced such a device as substantially fulfills the objects of the invention as set forth herein.

l llhile this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. A thermostatically controlled damper system comprising in combination with a normally closed thermostat switch arranged to open under the influence of heat, and a cirfcuit in which said switch is interposed; a

damper unit; said unit including a passage member, a shutter interposed' in said member, and electrically operated means interposed in said circuit and holding the shutter open when the switch is closed. p

2. A thermostatically controlled damper structure comprising a damper unit; said unit including a passage member, a shutter interposed in said member, means for holding the shutter open, and thermostat means actuated by the heat of air passing through the passage member for moving the shutter without affecting the functioning of said first named means.

3. A thermostatically controlled damper system comprising in combination with a pair of normally closed thermostat switches arranged to open independently with varying degrees of heat, and independent circuits in which said switches are interposed; a damper unit including a passage member, a shutter interposed in said member,independent electric magnets interposed in the circuits, a shutter operating structure, and means between the magnets and sai-d structure for causing the shutter to be opened to diflerent extents, dependingon which magnet is energized.

4. A damper structure including a passage member, a shutter therein, means for opening the shutter, and thermostatic means included with said first named means for moving the shutter regardless of the operation of said first named means.

5. A damper structure including a passage member, a shutter therein, means for initially opening the shutter, and an expansible thermostat element included with said first named means and connected tothe shutter to move the same when said element is influenced by heat adjacent said shutter.

6. A damper structure including a passage member, a shutter therein, an electroa" magnet, means between said magnet and the shutter for opening the latter when the magnet is energized, said means including any rotatable shaft, and an expansible thermostat element connected at one end to the shaft and at the other end to the shutter to both cause the shutter to be opened when the shaft is rotatedwith the energizing of the magnet .and to be opened irrespective of the movement of the shaft when ,said element is expanded by heat.

7. A- damper structure including a passage member, a shutter therein, means for opening the shutter, and an expansible thermostat element connected to the shutter to move the same when said element is influenced by heat adjacent said shutter, and arranged to avoid interfering with the operation of the first named means.

8. A damper structure including a pas sage member, axshutter therein, an independcnt pair of electro-magnets, a shutter openreeaoee ing structure including a movable rod, and independept means between the magnets and rod for causing the latter to be moved to difierent extents with the independent energizing of the magnets.

9. A damper structure including a pas sage member, a shutter therein, an independ- -..ent pair of elect-ro-magnets, a shutter opening structure including a movable rod, in-

energizing of the corresponding magnets.

10. A damper structure including a passage member, a shutter therein, means for opening the shutter, and hand means connected to saidfirst named means for oper ating the shutter arranged to function without affecting the first named means.

11. A. damper structure including a passage member, a turnable shutter therein, a shaft alined with the axis of the shutter but separate therefrom, a thermostat spiral member between the shaft and shutter, and electrical means for rotating the shaft.

12. damper structure including a passage member, a turnable shutter therein, a shaft alined with the axis ofthe shutter but separate therefrom, a thermostat spiral member between the shaft and shutter, electrical means for rotating the shaft in one direction to open the shutter, and spring means for moving the shaft in the opposite direction.

13. A damper structure including a passage member, a turnable shutter therein, a shaft alined with the axis of the shutter, connecting means between the shaft and sl utter, a pinion on the shaft, a rod, a rack p povided with the rod and engaging the pinion, and electrical means for moving the rod longitudinally.

14. A damper structure including a passage member, a shutter therein, an electromagnet, a shutter operating structure in cluding a. longitudinally movable rod, a finger straddling the rod, a stop member on therod outwardly of the finger, a transversely movable plate having a cam surface disposed between the finger and stop member, operative connections between the finger and magnet to cause said finger to bear against the plate and move the rod longitudinally when the magnet is energized, and means preventing the fingers from moving ing the'opposite' direction when the plate is moved.

15. A damper structure including a cylindrical drum having opposed side openings, a cylindrical shutter turnably mounted in the drum and having opposed openings to register with the drum-openings, a shaft for the shutter member, another shaft separate from but parallel to the firstshaft.

lE-ZO neeaoeo thermostat spiral member inside the shutter member connected at one end to the shutter shaft and at the other end to the inner end of said other shaft, and means for rotating said other shaft.

16, A- damper structure including a shutter, an electro-magnet, a shutter operating and magnet for causing the finger to bear against the stop to move the rod in a shutter opening direction when the magnet is energized, and stop means halting the return movement of the red when the magnet is deenergizeol, and the rod has moved toward but has not reached a shutter closing position.

17. A damper structure including a passage memher, a tnrnable shutter therein, a shaft axially alined with the shutter hut separate therefrom, means for turningthe shaft, and a thermostat spiral member hetWeen the shaft and shutter.

In testimony whereof ll afiix my signature.

IRA E. SMITH. 

